Tennis racket stringer



ug. 18, E936.

R. RosTRoN ET AL.

TENN

IS RACKET STRINGER Filed Feb. 3, 1935 Patented ug. 18, 1936 Unirse smits l'risNNiS RACKET' s'ijtl'ndiiit Robert Rostron, Chicago, and Harold Roberts,l Riverside i lill. Application February 3, 19%, ASerial No. 'YS

3 creams. (elites- 25)l 5 entirely hyhnd, except m a few instahoes where' or'riiiloatedI and expensive automatic machinery was avente-1e. l o

0 griostheehd of the ytreme and the handle. Two

igths 'of gut or other suitabiestring materiau aroused, one Afor making the longitudinal strings -id de' for the' cross'v'strngs. In starting the r operation, the iengthofgut is looped through the tw adjacent st riifig holes which are provided at the opts-ef hr of the frame, andtheh the two ends are worked' back ao forth through the otherl string' holes, proceeding from the two middle stiihgst'cwar'd the sides of the frame. As each sti-'ingis dawn through the proper hole, in each 'r'id ef the racket, Ythe gut is wrapped about three times around the hond or e wooden peg, end prirl'ld taut, the 4tension being roughly deter' mined er judged byt-wehgiog the string. Then s'ler'xd awl is worked through the hole',l beside the stri-rig', to hld the t-fns'iori until the next trii'ig is'V threaded back across the raclret and drawitig'ht. This is continued out to the sides fthe fratrie whereV the ends are iirialljr passed along" iii'idr several of the loopsu where the string passes from'o hole to the next at the outerside of` the frame',A and the end is tied to the lest loop. o When the longitudinal strings are all in place,

' the cross' strings are put in place' by knotting the end of the second length of gut in the first cross string hole at the top of the racket, and then strurg back and forth and woveny between the longitdlnal strings, each cross string being drawn to what is adjudged to be the desired tension,- and the awls inserted to hold the tension as the Stringing progresses. At the bottom of the racket frame, the end is brought out and secured to' the adjacent loops on the outside of the frame.

Numerous difficulties arise in handling the gut, holding theftension, and so on, so that it is obvious that even anindiierentjob of hand stringing requires considerable skill and experience, especially in obtaining vthe right tension in the strings,` Vtoprovide Vthe degree of resiliency to which a player is accustomed. An experts game depends greatly on the reaction of his racket, and it is therefore desirable to be able to string the racket to suit the player.

The racket frame is quite flexible, the frames being made as narrow as possible and also perfofated with a large number of closelyv spaced holes,

s that, iii drawing up the lengthwise strings, the frane is apt to be bowed out at the sides, and when the cross strings are tensidned, the sides are drawn back more' or less and the tension in the 5 long' strings is altc'ered.` A I Accordingly objects of the present invention are to prvide means for' holding the racket so that it is readily accessible from al1 sides, and for holding y it ag'an'st undue distortion during the Stringing. l0 Frther objects are to provide a puller Ywhich will hldtl strings after tightening and leave the f're 'to' insert the awls or holders, and to provide mear-'is for accurately determining the tiisio of each string.- Aiiother object is to prol5 vid ai holder' which dan be rotated so that the opeatfirwill nt have' tocontinua-lly change position'a's' he is lworking fror'ii one end of the racket to theother.VA Y

Further4 objects andv advantages will become 20 apparent in the following description,- with refer-` ence to the accompanying drawing, in which an illustrative embodiment of the invention is Fig. 1 is a side elevation of the device, with por- 2'5 tions broken. away, and parts shown in section;

Fig: 2 s a pla-nview of the same.

3 is adetai-l section on the line 3-'-3 of Fig. 1. Fig'. 4' is a section takenon the line 4-4 of Figfg.

A hat base' frame 5 has a hole 6, in the medial portion thereof, by which it may be rotatably secured, as by a bolt 1, toa table or other suitable support 8'; A-t one end ofthe base is provided a circular boss' |10 o'n which is rotatably mounted a vice frame I I, said frame having a circular turn table base portion I2 secured tothe fa'ce of the boss I0 by a stud I3, xedly secured in the center of thegb-o'ss, and a nut I4 which is threaded on the upper end of the stud which projects through the base I2. A disc of friction material I5 is inserted between the turntable and the face of the boss to prevent the vice from turning too freely.

, Extending upwardly from the turntable portionl l2 arefour armsv I6, I'I, I8,- and I9, at sub- 4'5 starrtially right angles to each other. The upper ends of the arms are provided with horizontally disposed bosses 2l! having at surfacesl 2| at the top thereof; and .on each of said dat surfaces is mounted a `clamp 22 which has a horizontal seating surface for supporting the racket J, and an upwardly projecting nger portion 24 which engages the frame K of the racket internally. The finger portions 24 are padded with felt 25a, and to avoid the string holes in the frame the fingers 55 are slotted at 26.

On the arm I6 the clamp is rigidly secured by a screw 21 which extends through the boss 20, and is threaded into the tail portion of the clamp. This particular clamp is used to engage in the bottom of the frame, adjacent to the handle L. In the remaining arms the clamps are adjustably secured by horizontally disposed screws 28, the clamps for engaging the sides of the frame, on the arms I1 and I9, being loosely mounted on theflat surface 2| so that they may be rotated slightly on the adjusting screw so that they may be shifted laterally to uncover the adjoining string holes.

At one side of the vice, and mounted on the opposite end of the base 8, is provided a string puller 33 for drawing the strings through the frame and tensioning the same. The puller comprises a drum 3| having a central shaft 32 which is rotatably mounted in and extends through a bearing bracket 33, iixedly mounted on thebase 5. On the outer end of the shaft 32 is removably secured a winding spool 34 on which is secured a friction facing band 35 of yielding material, such as soft rubber. Y

As shown more clearly in Fig. lnthe winding drum is mounted below the plane of the clamps 22 and a racket clamped therein so that the string is pulled radially outward and at an angle downwardly to permit the unobstructed insertion of string wedging means such as a fastening awl at the outer side of the string hole. When the string is tensioned bythe ratchet winding drum the racket as held by the clamps 22 is prevented from turning by the string which extends radially outward from the' axis of the clamping means.

In cooperative relation with the drum is a driving disc 36 which has a shaft 31 rotatably mounted in abearing bracket 38, fixed to the base in alignment with the bracket 33. In the inner face of the drum is a circular recess 3S in which is loosely engaged a circular fiange 40', formed on the inner face of the driving disc 36; and also formed in the inner face of the drum are two arcuate recesses, 4I and 42, in which are engaged oppositely disposed lugs 43 and 44, formed on the disc. A coiled spring 45 is inserted in each recess, 4I, 42, and the springs are compressed between the corresponding lugs and the opposite endsV of the channel recesses, so that, normally, the disc is urged in counterclockwise rotation, as viewed in Fig. I, with respect to the drum, with the lugs thereon in contact with the end walls of the recesses. i

A handle 50 is inserted in the outer end of the disc shaft 31, and a pawl 5I, pivotally mounted on the bracket 38, is provided for holding the disc in clockwise rotation, the pawl' being engageable, when thrown to the left, with a ratchet wheel 52 which is secured to the outer side of the disc 36.

A finger 46 is formed on the periphery of the driving disc, which indicates on a suitable scale 41, provided on the periphery of the drum, the rotational position of the drum with respect to the disc, and, consequently, the compression of the springs and the amount of torque applied to the drum. Y

kIn stringing a racket with a device of this invention, the racket is placedron the vice in the manner shown in Fig. 1 and Fig. 2. The clamp tion of the device as a whole.

on the arm I8 is then drawn outward so that the frame ofthe racket is gripped internally between the clamps on the arms I6 and I1. 'I'hen the clamps on the arms I1 and' I9 are tightened, and all of the clamps adjusted to hold the frame in the desired shape.

A length of gut is looped through the two string holes at the top of the racket, and awls are inserted in the holes beside the strings to prevent slipping. The strings are threaded across the frame and the ends, first one and then the other are wound around the drum spool 34, and drawn up tight by pulling the handle back until the index shows the desired tension. The retaining awls are inserted, and the ends threaded back and tightened, the vice being rotated to bring the free ends adjacent to the puller.

In connecting the free ends of the string to the drum, the bight of the string is placed over the spool, wrapped around under the same, and then crossed under therstanding portion of the string to form a lock against thesoft spool facing the handle is then pulled back to rotate the drumvagainst the tension of the springs. Until the string is tight, the drum turns freely with the disc, but when the string is tightened, the springs are further compressed since the drum is held back. The pull'on the handle is continued until the finger 46 moves over theV dial to the marking which indicates the desired tension,

which is held by the pawl 5I, leaving the hands free to insert the awls, or otherwise` secure the strings.

AManifestly, this inventionr greatly facilitates the Stringing. More*accuratelytensioned rackets can be obtained, and a greater degree of tension can be secured than is possible by the hand method, and less skill is required. `The vice may be rotated so that the operator does not have to change position in working from one side of the racket to the other, and the base' may also be swung about to obtain the most suitable posi--v 'Ihe frame'A is firmly held in place, and distortionninwdrawing up the strings is prevented. The tension is accurately determinable whether the strings are longor short, which is difficult without the pulling device because the shorter strings give a higher musicalvnote under the same tension. Y

Having thus described our invention, we claim:

1. A string tensioningrdevice for a portableV racket restringer comprisinga' pair of spaced bearings fixedly mounted on a base, a flanged disc disposed between the bearings and lhaving a drum shaft projecting through one bearing,` a string winding drum fixedly mounted on the outer end of the drum shaft, a driving disc ro-f tatably supported on said disc and having'a'drive shaft extending through the other bearing, a spring compressed between the discs, and a ratchet for holding the'drivingA disc against counter-rotation.

2. A device as described in claim 1 having means for indicating relative movement between the discs to show the tensioning of the string.

3. A device according to vclaim 2 including a stop for limiting counter movement between. the discs. Y ROBERT ROSTRON. A.

HAROLD W; ROBERTS@- 

